1st time turning necks question

[JimSC]

Today for the first time I have needed to turn the necks on brass. I was having a hard bolt closure on once fired Lapua 6BR brass in my new home build. I troubleshot it down to the OD of the neck after seating was .269. I have had a Hornady neck turning tool sitting on the shelf for a year but this was the first time I have had the need for it. I was nervous as heck about cutting into the shoulder and figuring this was just a skim cut I stopped 1mm short of the neck. I would guesstimate about 50% to 75% of the neck area had brass removed. Loaded rounds chamber fine now and necks are a uniform .268 OD.

My question is will stopping the cut just short of the shoulder give me any problems down the road ?

 

[ebb]

Yes the dreaded donut is supposed to appear shortly. I can't speak to this as I have cut into the shoulder just a little to avoid this. I guess if the bullet doesn't go down to the neck shoulder junction it may not be a problem.

 

[JimSC]

Yes the dreaded donut is supposed to appear shortly. I can't speak to this as I have cut into the shoulder just a little to avoid this. I guess if the bullet doesn't go down to the neck shoulder junction it may not be a problem.

thanks, I thought I remembered something like that. I checked and it looks like the bearing surface of the bullet, Berger 105 Hybrid, stops about 1 mm short of where I stopped. If it does become a problem I have a Wilson inside neck reamer that should take care of it. I will give the cases a close inspection before they are fired again and probably ream them just for conformities sake.

 

[ebb]

I don't think you will have a problem if you just watch it. cutting it out can't be that hard.

 

[jimmymac]

You don’t have to stop short of the shoulder. Kissing it is just fine. Take your time and adjust the stop until you get it just right. You may lose a couple pieces of brass, but that’s the price.

 

[Straightshooter1]

I had the same reservations about cutting into the neck due to warnings regarding neck separation. But some good sources convinced me that's it's OK to just touch the neck (a very slight cut into it) was best and would reduce (or maybe even eliminate) the issue of the donut. As I did move to cut slightly into the neck, I noticed the cutter is shaped so that it minimized the cutting into the neck and does it at the proper angle. Now after many firings (like 9 firings on my current brass) it's been working out just fine and no apparent evidence for my necks separating or an issue regarding donuts.

Initially, I had heard I should only remove about 80% - 90% so I just skimmed the cut to where there was a small amount that wasn't touched by the cutter. Trimming like that helped give me better consistency. But then I tried another approach that made more sense to me and that was to be sure to trim all of the neck so that it's all exactly the same all the way around, and I bought a tube micrometer to measure this that I'd know more precisely what I was doing. So now I'm trimming all my .308 brass down to .125 and that's made a significant difference in consistency in the chrono numbers as well and the groups. Apparently, the uniform thickness of the necks AND that the thinner necks putting less release resistance on the bullet has made that difference.

 

[JimSC]

Played with the adjustments and ended up with these. I forgot to add some citric when cleaning these and kind of glad I forgot it now. The cut portion really stands out on the dull brass. I kissed the shoulder with the angle portion of the cutter just enough to scrape the oxidation off

 

[mikecr]

My question is will stopping the cut just short of the shoulder give me any problems down the road ?

ANSWER:

I was having a hard bolt closure on once fired Lapua 6BR brass in my new home build.

 

[savageshooter86]

One on left looks about perfect

 

[Fotheringill]

Find out what the measurement for the OD should be for your round after sizing and trimming. Use a feeler gauge (to st the depth of the cut. I learned that on this board) and enjoy the PITA exercise in doing so.

 

[JimSC]

Well this has been a learning experience for sure, an educational experience that I was going to put off for a year but I was going to have to go through eventually. I am sure James told me it was a .268 neck when I bought the barrel but it just did not register. It went in one hearing aid and out the other. I went ahead and turned all the unloaded cases down to .265 and have a .265 and .264 bushings on order. I have another one hundred cases on the UPS truck as backups if I start to lose necks I will definitely be carrying a cleaning rod to the range in the future and it will take me a while to learn to trust my work

Thanks to the posters who have been kind enough to give me some tips

 

[cocopuff]

One on left looks about perfect

it has been my experience that necks do not need to be turned unless you have a tight chamber..